Knee implants having hydromagnetic joints

ABSTRACT

A knee implant includes a first implant part adapted for attachment to a femur and a second implant part adapted for attachment to a tibia. The knee implant includes a hydromagnetic joint having a first magnetic element with a first magnetically charged surface and a first buoyant element coupled with the first magnetic element, and a second magnetically charged surface that opposes the first magnetically charged surface of the first magnetic element and a second buoyant element coupled with the second magnetic element. A fluid body is disposed between the first and second buoyant elements, and the first and second buoyant elements are in fluid communication with one another through the fluid body. The hydromagnetic joint has an enclosure extending between the first and second buoyant elements for containing the fluid body therebetween, whereby the first and second buoyant elements are moveable relative to one another.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 13/046,949, filed Mar. 14, 2011, issued on even date herewithas U.S. Pat. No. 8,449,615, which is a continuation-in-part of U.S.patent application Ser. No. 13/031,566, filed Feb. 21, 2011, nowallowed, which, in turn, claims benefit of U.S. Provisional ApplicationSer. No. 61/325,357, filed Apr. 18, 2010, the disclosures of which arehereby incorporated by reference herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to joints and springs, and morespecifically relates to moveable joints and springs for mechanicalsystems and medical devices such as intervetebral implants and kneeimplants.

2. Description of the Related Art

A joint is a structure that joins together two separate parts. Somejoints unite the two parts rigidly, however, other joints permit motionbetween the two parts. Some joints are reinforced with nails, screws, orglue, such as a joint forming a connection between two pieces of wood ormetal.

In a human body, a joint is the moveable or fixed place where two bonesor elements of a skeleton are joined together. Recently, moveableartificial joints have been incorporated into medical implant devicessuch as artificial knees, artificial hips, and spinal implants such asintervertebral discs. By 2012, the joint reconstruction market isexpected to grow from $12.2 to $17.4 billion. By 2016, the spinalimplant market is expected to grow from $6.5 to $10.3 billion.

Metal rods and pedicle screws are often used during spinal fusionprocedures. Physiological drawbacks of using metal rods for spinalfusion include decreased motion, pain, degeneration of joints,stiffness, epidural searing and muscle stripping. Other drawbacksinclude the high costs associated with physical therapy andrehabilitation, and instances of post-surgical infection.

One problem with joints for mechanical systems and medical devices isthat they tend to wear out and must be replaced. Other problems includegel extrusion, joint/surface friction and bone resorption. Anotherproblem is that joints do not sufficiently dampen vibrational,compression and tension forces, resulting in energy losses and thegeneration of excessive noise. In addition, moveable artificial jointsdo not accurately replicate the natural movement of the human body.

In view of the above problems, there remains a need for improved jointsfor mechanical systems and medical devices that are durable, conserveenergy, sufficiently absorb vibrational, compression and tension forces,and minimize noise. Moreover, there is a need for hydromagnetic jointsthat increase physiological effectiveness by increasing motion, anddecrease friction and pain, and that decrease research and developmentand material costs, and increase durability.

SUMMARY OF THE INVENTION

In one embodiment, a hydromagnetic joint preferably includes a firstjoint part including a first magnetic element having a magneticallycharged surface, and a first buoyant element coupled with the firstmagnetic element, and a second joint part including a second magneticelement having a second magnetically charged surface that opposes thefirst magnetically charged surface of the first magnetic element, and asecond buoyant element coupled with the second magnetic element. Thejoint desirably includes a liquid, such as water or saline solution,disposed between the first and second joint parts, whereby the first andsecond joint parts are moveable relative to one another and are in fluidcommunication with the liquid.

In one embodiment, the liquid is contained within an enclosure that isdisposed between the first and second joint parts. In one embodiment,the enclosure for the liquid is flexible so that the shape of the liquidbody may change in response to external forces such as compression,tension and vibrational forces transferred from the first and secondjoint parts.

In one embodiment, as least one of the first and second joint partspreferably includes a solid body having at least one aperture extendingtherethrough that is adapted for enabling the liquid to pass through theat least one aperture. The at least one aperture may include a pluralityof apertures. The size and number of apertures may be modified forcontrolling the compression rate of the hydromagnetic joint. Forexample, if it is desirable to provide for more rapid compression of ahydromagnetic joint, more apertures may be provided through the body ofone of the first and second joint parts. The size or diameter of theapertures may also be modified for controlling the compression rate. Onthe other hand, if it is desirable to slow down the compression rate,fewer apertures or apertures having a smaller diameter may be provided.

In one embodiment, the first and second joint parts are moveablerelative to one another. In one embodiment, the first and second jointparts are preferably aligned with one another along an axis and aremoveable relative to one another along the axis.

In one embodiment, the magnetic elements comprise magnetic materialsincluding ferromagnetic, diamagnetic, and electromagnetic materials, orany other well-known magnetic materials.

In one embodiment, in response to compression forces, the first andsecond joint parts are adapted to move toward one another forcompressing the liquid therebetween. The first and second magneticallycharged surfaces desirably have the same polarity and are adapted torepel one another when the first and second parts are compressed towardone another.

In one embodiment, as the first and second joint parts are compressedtoward one another, the first and second joint parts transfer thecompressing force to the liquid. The flexible enclosure or flexiblediaphragm containing the liquid enables the shape of the liquid body tochange in response to the compression forces. The resistance provided bythe liquid body dampens the compression rate for the first and secondjoint parts. In addition, the first and second magnetically chargedsurfaces having the same polarity will repel one another when the firstand second parts move toward one another. The repelling force willincrease as the first and second magnetically charged surfaces movecloser to one another. Thus, the compression rate of the hydromagneticjoint is dampened by both the resistance provided by the liquid body andthe repelling magnetic force between the first and second joint parts.

In one embodiment, the hydromagnetic joint may be incorporated into amedical implant device such as a knee replacement implant, a hipreplacement implant, a bone implant, and/or a spinal implant such as anintervertebral device or a device that replaces one or more vertebrae.In one embodiment, a medical device having an electromagnetic joint maybe used to replace multiple vertebrae. In one embodiment, anintervertebral device has a near frictionless joint that preserves bothvertebral segment mobility as well as resisting axial compression. Thehydromagnetic joint desirably allows for gradual resistance to axialcompression that may not be achieved when using current disc replacementimplants. Additionally, wear is nearly absent in the device having ahydromagnetic joint because there is nearly no metal to metal contactand no risk of UHMW polyethylene wear. In addition, the hydromagneticsurface distributes force across the entire joint endplate to preventbone resorption, and gel extrusion seen in conventional devices cannotoccur with the device disclosed in the present application. Finally,competing implants are prone to fragmentation with shearing loads, whichis obviated with a spinal implant having a hydromagnetic joint.

In one embodiment, the hydromagnetic joint may also be incorporated intomechanical systems having moveable joints, such as car joints, powergeneration systems (e.g., generators), shoes and sneakers, and balanceboards used for medical therapy.

It may be desirable to secure the hydromagnetic joint in place within amechanical system or a patient's body. For example, a bore may be formedin bone and the anchoring element may be inserted into the bone forholding the hydromagnetic joint to the bone. The anchoring elementdisposed within the bone may include a hydromagnetic joint for dampeningcompression, tension, and vibrational forces. In one embodiment, ahydromagnetic joint preferably includes a first anchoring elementcoupled with the first joint part for anchoring the first joint part toa first object, and a second anchoring element coupled with the secondjoint part for anchoring the second joint part to a second object. Inone embodiment, a hydromagnetic joint may be incorporated into ananchoring element.

In one embodiment, a medical implant preferably includes a first partincluding a first magnetic element having a magnetically charged surfaceand a first buoyant element coupled with the first magnetic element, asecond part including a second magnetic element having a secondmagnetically charged surface that opposes the first magnetically chargedsurface of the first magnetic element and a second buoyant elementcoupled with the second magnetic element, and a liquid body disposedbetween the first and second parts, whereby the first and second partsare in fluid communication with the liquid body and are adapted to moverelative to one another.

The first and second magnetically charged surfaces desirably have acommon polarity so that the first and second magnetically chargedsurfaces repel one another. The medical implant preferably includes afirst anchoring element coupled with the first part of the implant forattaching the first part to a first bone, and a second anchoring elementcoupled with the second part of the implant for attaching the secondpart to a second bone. In one embodiment, the first and second parts ofthe implant move relative to one another. In one embodiment, one of thefirst and second implant parts may remain stationary and the other oneof the first and second implant parts is moveable relative to the otherimplant part. In one embodiment, the stationary implant part includes arelatively rigid or stationary reservoir for holding the liquid and theother implant part moves in a fashion similar to a piston within thereservoir. In one embodiment, the moveable implant part includes one ormore apertures extending therethrough for enabling the liquid to passthrough the apertures as the implant parts move toward one another. Thesize and/or the number of apertures provided will control thecompression rate of the hydromagnetic joint. As noted above, the numberof apertures and the size of the apertures may be modified to change thecompression rate. The hydromagnetic joint may have shutters formodifying the size and/or the number of the apertures to change thecompression rate of the joint, which may occur after the joint has beeninstalled or implanted. In one embodiment, the shutters may be openedand closed and adjusted by a control system such as an electroniccontrol system.

In one embodiment, an enclosure desirably extends between the first andsecond parts for containing the liquid body. The enclosure may beflexible for changing shape as the first and second parts move relativeto one another.

In one embodiment, a balance board for providing balancing therapydesirably includes a first part having a first buoyant element, and afirst magnetic element attached to the first buoyant element, the firstmagnetic element having a first magnetically charged surface, and asecond part including a second buoyant element, and a second magneticelement attached to the second buoyant element, the second magneticelement having a second magnetically charged surface that opposes andrepels the first magnetically charged surface. The balance boardpreferably includes a liquid body contained between the first and secondparts with the first and second parts being in fluid communication withthe liquid body and being adapted to move relative to one another.

In one embodiment, the balance board is used for rehabilitation and isparticularly used for rehabilitating military personnel having amputatedlimbs. Placing the above-described balance board with a hydromagneticjoint in an external body of water has been shown to enhance balancingtherapy for the above-described military personnel. In one embodiment,the balance board is held below the surface of the external body ofwater using restraining straps. The restraining straps perform a numberof functions including holding the balance board below the top surfaceof the external body of water and limiting vertical and horizontalmovement of the balance board within the external body of water.

In one embodiment, an intervertebral implant preferably includes a firstpart attached to a first vertebrae, the first part including a firstmagnetic element having a first magnetically charged surface and a firstbuoyant element coupled with the first magnetic element, and a secondpart attached to a second vertebrae, the second part including a secondmagnetic element having a second magnetically charged surface thatopposes the first magnetically charged surface of the first magneticelement and a second buoyant element coupled with the second magneticelement. The implant desirably includes a fluid body, such as a liquidor gel, disposed between the first and second parts, whereby the firstand second parts are in fluid communication with one another through thefluid body. An enclosure, such as a flexible enclosure, preferablyextends between the first and second parts for containing the fluid bodytherebetween, whereby the first and second parts are preferably moveablerelative to one another.

In one embodiment, the intervertebral implant desirably includes a firstanchoring element coupled with the first part of the implant forattaching the first part to the first vertebrae, and a second anchoringelement coupled with the second part of the implant for attaching thesecond part to the second vertebrae.

In one embodiment, the first and second magnetically charged surfacesoppose one another and have a common polarity so that the first andsecond magnetically charged surfaces repel one another. The repellingforces may be useful for dampening compression forces exerted upon thefirst and second implant parts.

In one embodiment, the flexible enclosure is adapted to change shape asthe first and second parts move relative to one another. The fluid bodyand the flexible enclosure are adapted to change shape in response tocompression forces exerted upon the first and second parts of theintervertebral implant.

In one embodiment, an intervertebral implant desirably includes a firstimplant part with a first magnetic element having a magnetically chargedsurface, and a first buoyant element coupled with the first magneticelement, and a second implant part opposing the first implant part, thesecond implant part including a second magnetic element having a secondmagnetically charged surface that opposes the first magnetically chargedsurface of the first magnetic element, and a second buoyant elementcoupled with the second magnetic element. The first and secondmagnetically charged surfaces preferably have the same polarity and areadapted to repel one another. The intervertebral implant preferablyincludes a fluid disposed between the first and second implant parts,whereby the first and second implant parts are moveable relative to oneanother and are in fluid communication with one another via the fluid.

In one embodiment, at least one of the first and second implant partscomprises a solid body having at least one aperture extendingtherethrough adapted for enabling the fluid to pass through the at leastone aperture. The at least one aperture may include a plurality ofapertures.

In one embodiment, the first and second parts of the intervertebralimplant are moveable relative to one another. The first and second partsare preferably aligned with one another along an axis and are moveablerelative to one another along the axis. In one embodiment, the first andsecond parts are adapted to move toward one another for compressing thefluid therebetween.

In one embodiment, the intervertebral implant preferably includes afirst anchoring element coupled with the first part for anchoring thefirst part to the first vertebrae, and a second anchoring elementcoupled with the second part for anchoring the second part to the secondvertebrae.

In one embodiment, an intervertebral implant desirably has a first partincluding a first magnetic element having a magnetically charged surfaceand a first buoyant element coupled with the first magnetic element, anda second part including a second magnetic element having a secondmagnetically charged surface that opposes the first magnetically chargedsurface of the first magnetic element and a second buoyant elementcoupled with the second magnetic element. The implant preferablyincludes a fluid disposed between the first and second parts, wherebythe first and second parts are in fluid communication with the fluid andare adapted to move relative to one another. The intervertebral implantdesirably includes an enclosure extending between the first and secondparts for containing the fluid. The enclosure is desirably flexible forchanging shape as the first and second parts move relative to oneanother.

In one embodiment, the flexible enclosure of the intervertebral implantis adapted to leech a medical solution such as a medicated fluid,liquid, or gel into the area of the spine surrounding the implant. Incertain preferred embodiments, the fluid, liquid or gel may be amedicated solution including but not limited to analgesics,anti-inflammatories, steroids, antibiotics, etc. The flexible enclosurepreferably functions as a reservoir for the medicated fluid, liquid orgel. The reservoir may be re-filled just as pain pumps are re-filledtoday.

After most disk replacement surgeries, a massive amount of painmedication is used, however, patients that receive the medicatedintervertebral implant disclosed herein will be pain free. In oneembodiment, when increased compression of the intervertebral implantoccurs, more medication would be leeched out to inflammatory sitesdecreasing degeneration in the surrounding area. In one embodiment, theintervertebral implant has a microscopic two way opening that allows themedication to leech out and the device to be re-filled. In oneembodiment, the implant has a first fluid chamber that does not leech sothat the level of fluid therein remains constant and a second fluidchamber that leeches medication. The second fluid chamber that leechesmedication is preferably re-fillable.

These and other preferred embodiments of the present invention will bedescribed in more detail below.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 shows a system including a hydromagnetic joint for dampeningcompression, tension and vibrational forces, in accordance with oneembodiment of the present invention.

FIG. 2 shows a medical implant including a hydromagnetic joint, inaccordance with one embodiment of the present invention.

FIGS. 3A and 3B show an artificial knee implant including ahydromagnetic joint, in accordance with one embodiment of the presentinvention.

FIG. 4 shows a schematic of the medical implant and hydromagnetic jointof FIG. 2.

FIGS. 5A and 5B show an artificial knee implant including thehydromagnetic joint of FIG. 3B implanted in a patient.

FIG. 6 shows an artificial intervertebral disc having a hydromagneticjoint, in accordance with one embodiment of the present invention.

FIG. 7A shows a balance board including a hydromagnetic joint, inaccordance with one embodiment of the present invention.

FIG. 7B shows a patient positioned atop the balance board of FIG. 7A forbalancing therapy, in accordance with one embodiment of the presentinvention.

FIG. 8 shows a balance board including a hydromagnetic joint, inaccordance with another embodiment of the present invention.

FIG. 9 shows a spring including a hydromagnetic joint, in accordancewith one embodiment of the present invention.

FIG. 10 shows a vehicle including a shock absorbing system having one ormore hydromagnetic joints, in accordance with one embodiment of thepresent invention.

FIG. 11 shows a shoe including a heel having a hydromagnetic joint, inaccordance with one embodiment of the present invention.

FIGS. 12A and 12B show a power generation system including a generatorpositioned atop hydromagnetic joints, in accordance with one embodimentof the present invention.

FIG. 13 shows an artificial knee including a hydromagnetic jointdisposed in a bone anchoring element, in accordance with one embodimentof the present invention.

FIG. 14 shows a hydromagnetic joint having apertures that control thecompression rate of the joint, in accordance with another embodiment ofthe present invention.

FIG. 15 shows an intervertebral disc having a hydromagnetic jointincluding a fluid reservoir adapted to leech a medicated solution, inaccordance with one embodiment of the present invention.

FIG. 16 shows an intervertebral disc having a hydromagnetic jointincluding a first reservoir for a fluid and a second reservoir adaptedto leech a medicated solution.

DETAILED DESCRIPTION

Referring to FIG. 1, in one embodiment, a hydromagnetic joint 20includes a first buoyant element 22 having a top surface 24 and a bottomsurface 26. The first buoyant element 22 is preferably buoyant in aliquid such as water. The hydromagnetic joint 20 also preferablyincludes a first magnetic element 28 having a negatively charged surface30, and a positively charged surface 32.

The hydromagnetic joint 20 also desirably includes a body of a liquid34, such as water, saline solution, or gel, bounded by a flexibleenclosure 36, such as a flexible diaphragm, that enables the liquid body34 to change shape in response to compression, tension, and vibrationalforces applied to the hydromagnetic joint. The flexibility of thediaphragm may be varied in response to operational needs. In oneembodiment, the hydromagnetic joint preferably includes a compressiblefluid such as a compressible gas or a compressible liquid. In oneembodiment, the compressibility of the fluid or liquid may be varied.

The hydromagnetic joint 20 also desirably includes a second buoyantelement 38 having a top surface 40 and a bottom surface 42. The secondbuoyant element desirably has properties that are similar to the firstbuoyant element 22 so that it is adapted to float atop a liquid, such aswater. The hydromagnetic joint 20 also desirably includes a secondmagnetic element 44 having a positively charged top surface 46, and anegatively charged bottom surface 48. The first and second magneticelements 28, 44 are preferably made of ferromagnetic, diamagnetic,electromagnetic, or other well-known magnetic materials.

In the embodiment shown in FIG. 1, the positively charged surfaces ofthe first and second magnetic elements 28, 44 face one another. In otherembodiments, however, the orientation of the first and second magneticelements may be changed so that the opposing faces are negativelycharged surfaces. The principal of operation remains consistent so longas the opposing faces of the first and second magnetic elements havecommon polarities so that they repel one another. The repelling forcepreferably increases as the opposing magnetically charged surfaces movecloser to one another.

Although the present invention is not limited by any particular theoryof operation, it is believed that the hydromagnetic joint 20 shown inFIG. 1 utilizes magnetism, buoyancy, and hydraulics to provide a nearlyfrictionless joint capable of preserving both mobility as well asminimizing energy losses. The first and second magnetic elements providea repelling magnetic force as the magnetic elements are compressedtoward one another. The first and second buoyant elements also provide adampening force in response to compression of the buoyant elementstoward one another. The hydromagnetic joint 20 exhibits gradualresistance to compression in a manner that cannot be achieved withconventional mechanical implants. The level of resistances may increaseas the joint is further compressed. Moreover, the potential forstructural breakdown of the joint elements is greatly minimized orreduced.

When the first and second buoyant elements 22, 38 are compressed towardone another, the interaction of the buoyant elements 22, 38 with theliquid body 34 generates a dampening or repelling force that opposes thecompression forces. In addition, the opposing magnetic elements 28, 44that are coupled with the respective first and second buoyant elements22, 38 also provide a repelling force as shown by the large arrow inFIG. 1. Moreover, an electric field generated by the moving magneticelements 28, 44 may yield additional energy that can be harnessed andutilized.

Referring to FIG. 2, in one embodiment, a hydromagnetic joint 120 may beincorporated into a medical device such as an artificial knee. In oneembodiment, a femur bone 50 has a lower end 52 and a tibia bone 60 hasan upper end 62. The artificial knee including the hydromagnetic joint120 preferably includes a first buoyant element 122, and a firstmagnetic element 128 coupled with the first buoyant element 122. Thefirst magnetic element has a negatively charged face 130 and apositively charged face 132. The first buoyant element 122 and the firstmagnetic element 128 are preferably coupled together for movingsimultaneously with one another. The hydromagnetic joint 120 desirablyincludes a liquid body 134, such as a body of water, contained within aflexible enclosure 136 for enabling movement of the liquid body inresponse to compression, tension, and vibrational forces.

The artificial knee with the hydromagnetic joint 120 also desirablyincludes a second buoyant element 138 coupled with the upper end 62 ofthe tibia 60, and a second magnetic element 144 coupled with the secondbuoyant element. The second magnetic element 144 includes a negativelycharged face 148 and a positively charged face 146. The positivelycharged face 132 of the first magnetic element 128 desirably opposes thepositively charged face 146 of the second magnetic element 144 toprovide a magnetic repelling force between the first and second magneticelements 128, 144. In other embodiments, however, the opposing surfacesof the first and second magnetic elements 128, 144 may be negativelycharged for repelling one another.

In one embodiment, the femur 50 and the tibia 60 compress thehydromagnetic joint 120 therebetween so that a compressing force F₁ isapplied to the liquid body 134. In response, the first and secondbuoyant element 122, 138 provide a repelling and/or dampening force thatresists compression and the opposing positively charged faces of thefirst and second magnetic elements 128, 144 provide a repelling magneticforce. The combination of the repelling magnetic and buoyant forces isdesignated F₂.

FIG. 3A shows a human leg including the femur 50 and the tibia 60. Anatural knee joint 70 is located between a lower end 52 of the femur 50and an upper end 62 of the tibia 60. FIG. 3B shows the leg of FIG. 3Aafter the artificial knee including the hydromagnetic joint 120 of FIG.2 has been implanted between the lower end 52 of the femur 50 and theupper end 62 of the tibia 60.

FIG. 4 shows a schematic view of the artificial knee implant including ahydromagnetic joint 120 positioned between the femur bone 50 and thetibia bone 60. The hydromagnetic joint 120 is represented in FIG. 4 as abox having an X positioned therein. The schematic showing ahydromagnetic joint 120 as a box with the X positioned therein is doneto enhance clarity as to where the hydromagnetic joint is positioned inother embodiments disclosed herein.

Referring to FIG. 5A, in one embodiment, a patient 80 has a legincluding a femur 50 and a tibia 60. An artificial knee including ahydromagnetic joint 120 is implanted between the lower end of the femur50 and the upper end of the tibia 60 to provide a flexible hydromagneticjoint. The hydromagnetic joint is preferably flexible during movement ofthe patient's leg and dampens compression, tension and vibrationalforces.

FIG. 5B shows an artificial knee with the hydromagnetic joint 120 duringmovement of the patient 80. The hydromagnetic joint 120 is adapted toaccommodate flexing of the knee area of the patient and responds tocompressive forces with opposing dampening and/or repelling forcescreated by the opposing buoyant elements and the opposing magneticelements.

Referring to FIG. 6, in one embodiment, a hydromagnetic joint may beincorporated into an intervertebral disc implant that is positionedwithin a disc space of a vertebral column. In FIG. 6, the vertebralcolumn 90 includes vertebra 92A-92E having intervertebral discs 94A-94Etherebetween. After disc 94C has been removed, an implant having ahydromagnetic joint 220 such as that shown and described herein may bepositioned within the disc space between vertebra 92C and 92D. Thehydromagnetic joint 220 of the implant provides flexibility between theadjacent vertebra 92C, 92D, while counteracting compressing forces dueto the repelling forces generated by the hydraulic forces generated bythe buoyant elements and magnetic elements of the joint 220.

In one embodiment, the hydromagnetic joint disclosed herein may beincorporated into a balance board used for balancing therapy. Referringto FIG. 7A, in one embodiment, a balance board 300 includes a topsurface 302 and a bottom surface 304 with a hydromagnetic joint 320positioned between the respective top and bottom surfaces 302, 304. Thehydromagnetic joint includes a first buoyant element 322 including thetop surface 302 and a first magnetic element 328 coupled with the firstbuoyant element 322. The first magnetic element 328 includes anegatively charged surface 330 and a positively charged surface 332. Thehydromagnetic joint also desirably includes a second buoyant body 338that is coupled with a second magnetic element 344 having a positivelycharged surface 346 and a negatively charged surface 348. Thehydromagnetic joint 320 desirably includes a liquid body 334 that iscontained between the first and second buoyant bodies 322, 338.

FIG. 7B shows a balance board 300 having the hydromagnetic joint 320shown in FIG. 7A. An individual, such an amputee undergoing balancingtherapy, may stand on the top surface 302 of the balance board 300. Thebalance board 300 is preferably immersed in an external body of waterand held below the waterline via straps 375 that limit horizontal andvertical movement of the balance board 300 within the external body ofwater.

Referring to FIG. 8, in one embodiment, a patient 480 may use a balanceboard 400 for therapy. For example, a patient 480, having one or morelimbs amputated, uses the board for balancing therapy to enhancebalancing capabilities and prepare the patient for receiving prostheticlimbs. In FIG. 8, the balance board 400 includes a first buoyant element422, a first magnetic element 428, a second buoyant element 438 and asecond magnetic element 444. A liquid body 434 is disposed between thefirst and second magnetic elements 428, 444. In one embodiment, aflexible membrane 436 holds the liquid body 434 between the first andsecond magnetic elements 428, 444 and enables movement of the liquidbody in response to compression and tension forces. The first magneticelement 428 has a first positively charged surface 432 and the secondmagnetic element 444 has a second positively charged surface 446 thatopposes the first positively charged surface. In one embodiment, thepatient 480 may wear boots 495 that have magnets incorporated thereinthat are magnetically attracted to the first magnetic element 428 for atleast partially holding the patient 480 atop the balance board 400. Thebalance board 400 is desirably immersed in an external body of water496. The balance board 400 is buoyant in the external body of water 496so that the patient 480 may balance on a top surface 402 of the balanceboard 400 for participating in balancing therapy.

Thousands of U.S. Service members have been wounded in Iraq. Thesecombat survivors often sustain multiple traumas and develop physical andmental injuries. The term olytrauma refers to concurrent injury to thebrain and several body areas or organ systems that result in physical,cognitive, and psychosocial impairments. While many therapeuticmodalities are available for patients with polytrauma, only a fewmodalities simultaneously address global rehabilitation, including pain,vestibular impairment, and cognitive symptoms. The sport of surfinginvolves aspects of hydrotherapy, strength training, balancerehabilitation, and group supportive therapy.

Surfing therapy may be used to help patients improve their proficiencyin walking, balancing, and vestibular functions, as well as gainmuscular strength, aerobic endurance, concentration, and timing of wavemovements. The devices shown in FIGS. 7A-7B and 8 of the presentapplication may be used as part of a surfing therapy protocol as part ofa multi-modal treatment for patients with polytrauma.

Surfing therapy provides patients, such as amputees, with an environmentand means by which to engage in physical activities they enjoy and whichchallenge them physically, mentally, and emotionally. It preferablyincludes vestibular instruction, water safety, swimming, paddling, andwave riding and focuses on the physical and psychological skills neededfor these activities, including balance, muscular strength, aerobicendurance, as well as skills in concentration and timing of wavemovement. Discussions among veteran mentors, who are also woundedwarriors, local lifeguards, and new program participants may also takeplace while participating in surfing therapy.

Although the present invention is not limited by any particular theoryof operation, it is believed that there are several potential mechanismsby which surfing may help patients. Pain management is most likelyestablished through endogenous opioid pathways that increase withexercise. It is unclear why patients may report greater improvements inpain with surfing than with other forms of exercise; it may, however, goalong with theories of long-term potentiation. The patients enjoy—andare excited by—their time surfing. Pleasurable experiences areassociated with increases in norepinephrine and serotonin, and thesepathways may, in turn, feedback on long-term potentiating and pain.

The most encouraging aspect of surfing as therapy may be its impact onvestibular function. Traditional vestibular rehabilitation involves theuse of a balance platform. While this platform may be helpful, manypatients feel they “max the machine” early on. In other words, therehabilitation challenges are not as strenuous as are the tasks that apatient may face in the real world. Surfing allows additional progress.The task of surfing is similar to that encountered on a traditionalbalance board, with the additional feature of movement. This may moreclosely approximate the problem of walking with a prosthetic, and othercomplicated vestibular issues. New developments will be required torecreate the vestibular challenge of walking without the ocean. Patientsmay be able to show greater, real-world progress after mastering the artof surfing.

It is also believed that surfing therapy may improve psychologicalsymptoms. This may be because surfing combines two modalities often usedtoday to assist in psychiatric illness: components of group therapy andexercise. In one embodiment, trauma survivors may congregate on shore tolearn the mechanics of surfing and also to communicate with each otherwhile they wait to catch the next wave. Interspersed with the waitingand talking are the strenuous exercise and excitement of actuallycatching a wave. Large muscular movements can increase the body'sserotonin norepinephrine and dopamine neurotransmitters. Excitement isalso independently associated with increases in both of theseneurotransmitters. These neurotransmitter systems are commonly decreasedin PTSD and depression, and it is possible that surfing helps normalizethese systems.

Surfing therapy has great potential for multi-modal treatment forpatients with polytrauma. Additional research and development is neededto see if the therapeutic benefit, including vestibular/balanceenhancement, pain resolution, and behavioral improvement, isattributable to participating in surfing therapy. In addition, for thosepatients not located near the ocean, additional research is required todetermine if new balancing devices (e.g. the embodiments shown in FIGS.7A-7B and 8) and new prosthetics may be used to translate the surfingexperience and benefits to a therapy pool at rehabilitation centers notlocated near the ocean.

Referring to FIG. 9, in one embodiment, a hydromagnetic joint 520 may beutilized as a spring. In one embodiment, the hydromagnetic joint 520 isdesirably positioned between a first shaft 550 and a second shaft 560 ofa mechanical system. The hydromagnetic joint 520 includes a firstbuoyant element 522 attached to the first shaft 550, a first magneticelement 528 coupled with the first buoyant element, a liquid body 534, asecond magnetic element 544 and second buoyant element 538 attached tothe second shaft 560. The first magnetic element 528 is desirablycoupled with the first buoyant element 522. The liquid body 534 ispreferably positioned between the first and second magnetic elements528, 544 and bounded by a flexible diaphragm 536. The second magneticelement 544 is preferably coupled with the first buoyant element 538,which, in turn, is connected with the second shaft 560. The first andsecond magnetic elements 528, 544 have opposing positively chargedsurfaces 532, 546. In operation, as the first and second shafts 550, 560move toward one another for compressing the hydromagnetic joint 520therebetween, the magnetic elements 528, 544 repel one another and thebuoyant elements 522, 538 use hydraulic forces to dampen compression viathe liquid body 534.

Referring to FIG. 10, in one embodiment, a vehicle 600, such as a truckor car, may include one or more hydromagnetic joints 620 that are usedin lieu of, or incorporated into, springs or shock absorbers forproviding a dampening force during operation of the vehicle 600.

Referring to FIG. 11, in one embodiment, a shoe or sneaker 700 may havea hydromagnetic joint 720 incorporated therein for providing cushioningand/or dampening forces. In one embodiment, the hydromagnetic joint 720is incorporated into the heel region 725 of a shoe or sneaker forcounteracting compression forces on the heel.

Referring to FIGS. 12A and 12B, in one embodiment, a power generationsystem includes a generator 800 such as a gas or diesel poweredgenerator. The generator vibrates during operation, which may causeexcessive noise and energy loss. In one embodiment, a plurality ofhydromagnetic joints 820 may be positioned to support the generator forcounteracting the vibrational forces created during operation of thegenerator. The hydromagnetic joints desirably minimize and/or eliminatevibration of the generator 800, which minimizes noise, and saves heatenergy losses due to less vibration of the generator 800. As such, thehydromagnetic joints 820 will provide for more efficient and quieteroperation of a generator. In one embodiment, additional hydromagneticjoints may be positioned beneath the generator 800 for minimizingvibration.

Referring to FIG. 13, in one embodiment, a hydromagnetic joint 920 maybe incorporated into a medical device such as an artificial knee 950.The artificial knee 950 desirably includes a first implant part 952secured to a lower end of a femur and a second implant part 954 securedto an upper end of a tibia. The second implant part 954 desirablyincludes an anchoring post 956 that is inserted into a bore 958 formedat the upper end of the tibia. The anchoring post 956 desirably has ahydromagnetic joint 920 disposed therein for absorbing compression andtension forces exerted upon the artificial knee 950. In otherembodiments, the hydromagnetic joint 920 may be disposed within ananchoring post associated with the first implant part 952. Although FIG.13 shows a hydromagnetic joint integrated into an artificial knee, oneor more hydromagnetic joints may be integrated into other medicaldevices such as a hip replacement device or a spinal implant.

Referring to FIG. 14, in one embodiment, a hydromagnetic joint 1000preferably includes a mobile element 1002 and a stationary element 1004.The mobile element 1002 preferably includes an outer wall 1010 thatdefines an enclosed internal chamber 1012. The mobile element 1002preferably includes a first shaft 1050 coupled with the mobile element1002. The mobile element 1002 also desirably includes a first buoyantelement 1022 and a first magnetic element 1028 coupled with the firstbuoyant element. The first magnetic element 1028 preferably has anegatively charged major face 1030 and a positively charged major face1032. The mobile element 1002 also desirably includes one or moreapertures 1035 that extend through the first buoyant element 1022 andthe first magnetic element 1028. The size and the number of apertures1035 may be modified to control the flow rate of a liquid through theapertures, which, in turn, controls the compression rate of the joint.The size of the apertures or the number of apertures that are open maybe controlled by a control system, such as an electronic control systemhaving one or more central processing units.

The stationary element 1004 preferably includes a second shaft 1060 andan outer wall 1065 that extends away from the second shaft to an opening1067 located at an upper end of the outer wall 1065. The stationaryelement 1004 preferably includes a second buoyant element 1038 and asecond magnetic element 1044 coupled with the second buoyant element.The second magnetic element 1044 includes a positively charged majorsurface 1046 and a negatively charged major surface 1048. The positivelycharged major surface 1046 of the second magnetic element 1044preferably opposes the positively charged major surface 1032 of thefirst magnetic element 1028 so that the first and second magneticelements repel one another. In one embodiment, the first and secondmagnetic elements may have negatively charged magnetic surfaces thatoppose one another. A liquid 1034 preferably fills a space between thesecond magnetic element 1044 and the opening 1067 at the upper end ofthe outer wall 1065.

In operation, as the mobile element 1002 is compressed toward thestationary element 1004 by a compressing force F₁, the liquid 1034passes through the apertures 1035 of the mobile part and fills theinternal chamber 1012. As the mobile element 1002 continues to movetoward the stationary element 1004, additional liquid 1034 passesthrough the apertures 1035 and fills the internal chamber 1012. As notedabove, the size of the apertures 1035 will control the rate of theliquid flowing through the apertures. The size and/or number ofapertures 1035 may be modified for controlling the rate of liquidpassing therethrough, which, in turn, controls the compression rate ofthe hydromagnetic joint.

At a particular stage of compression, fluid completely fills theinternal chamber 1012 of the mobile element for stopping furthermovement of the mobile part relative to the stationary element. At thisstage, the liquid is not flexible, thereby stopping the mobile element1002 before coming into contact with the stationary element 1004,leaving a small amount of liquid 1034 in between the mobile element andthe stationary element at full compression.

In one embodiment, a hydromagnetic joint may be disposed within a tube,diaphragm, bag or outer casing so that magnets do not become misalignedand so that the diaphragm does not extend beyond a certain diameter whencompressed. In one embodiment, the closer a tube or outer casing islocated to the hydromagnetic joint, the more the joint functions as ahydraulic piston.

In one embodiment, the enclosure for a hydromagnetic joint is flexible.In one embodiment, however, when the mobile element is fully compressedtoward the stationary element, the flexible enclosure for the liquid isno longer flexible and the liquid between the mobile and stationaryelements functions as a hydraulic stop for halting movement of themobile element before it comes in contact with the stationary element.

At a particular stage of compression, the opposing positively chargedfaces of the first and second magnetic elements 1028 and 1044 repel oneanother to push the mobile part 1002 away from the stationary element1004 by a force designated F₂. As the mobile element 1002 and thestationary element 1004 move away from one another, the liquid 1034 isdrawn from the internal chamber 1012 and passes through the apertures1035 for filling the central chamber of the stationary element 1004. Thehydromagnetic joint shown in FIG. 14 may be incorporated into any of theembodiments disclosed in the present application including medicalimplant devices.

When using conventional disk replacement devices, medication such aspain medication is typically used to provide pain relief. Referring toFIG. 15, in one embodiment of the present invention, an intervertebralimplant 1120 includes an enclosure 1136 that is adapted to leech amedical solution 1134 such as a medicated fluid, liquid, or gel into thearea of the spine surrounding the implant. In certain preferredembodiments, the fluid, liquid or gel may be a medicated solutionincluding but not limited to analgesics, anti-inflammatories, steroids,antibiotics, etc. The flexible enclosure 1136 preferably functions as areservoir for the medicated fluid, liquid or gel. The reservoir may bere-filled using one or more resealable openings 1155 that extend throughthe outer wall of the flexible enclosure 1136. In one embodiment, theenclosure 1136 is porous or includes one or more microscopic openingsfor allowing the medicated solution to slowly pass through the outerwall of the enclosure and into the surrounding tissue and bone. Theenclosure may also include one or more fill ports for re-filling theenclosure with the medicated fluid, solution or gel.

In one embodiment, when increased compression of the intervertebralimplant 1120 occurs, more medication would be leeched out from theenclosure 1136 to inflammatory sites decreasing degeneration in thesurrounding area and increasing acceptance of the implant. In oneembodiment, the intervertebral implant has a microscopic two way opening1155 that allows the medication to leech out and the device to bere-filled.

Referring to FIG. 16, in one embodiment, an intervertebral disc implant1220 has a first fluid chamber 1236 that contains a fluid 1234 that doesnot leech so that the volume of fluid therein remains constant therein.The implant 1220 preferably has a second fluid chamber 1237 adapted toleech a medicated solution 1239 after implantation. The second fluidchamber that leeches medication is preferably re-fillable via one ormore resealable openings 1255. The openings for leeching may bepositioned around the perimeter of the enclosure for providing themedicated solution completely around the implant.

In one embodiment, a system or medical device having a hydromagneticjoint preferably conserves vibrational energy by transferring dampeningor repelling energy into at least some of the energy used for apatient's next step or a system's (e.g., a generator) next cycle. Forexample, when a medical implant having a hydromagnetic joint iscompressed, the dampening and/or repelling magnetic forces may beharnessed for transferring energy into the patient's next step. Just asa runner can have a spring in his or her step when moving from touchinghis or her toes to standing upright, a medical implant having ahydromagnetic joint may provide a spring in its upward motion as it goesfrom a compressed state to an expanded state. The conserved energy mayalso be used for rotating a rotating generator.

While the foregoing is directed to embodiments of the present invention,other and further embodiments of the invention may be devised withoutdeparting from the basic scope thereof, which is only limited by thescope of the claims that follow. For example, the present inventioncontemplates that any of the features shown in any of the embodimentsdescribed herein, or incorporated by reference herein, may beincorporated with any of the features shown in any of the otherembodiments described herein, or incorporated by reference herein, andstill fall within the scope of the present invention.

What is claimed is:
 1. A knee implant comprising: a first implant partadapted for attachment to a femur; a second implant part adapted forattachment to a tibia; said knee implant including a hydromagnetic jointcomprising a first magnetic element having a first magnetically chargedsurface and a first buoyant element coupled with said first magneticelement, a second magnetically charged surface that opposes said firstmagnetically charged surface of said first magnetic element and a secondbuoyant element coupled with said second magnetic element, a fluid bodydisposed between said first and second buoyant elements, wherein saidfirst and second buoyant element are in fluid communication with oneanother through said fluid body, and an enclosure extending between saidfirst and second buoyant elements for containing said fluid bodytherebetween, wherein said first and second buoyant elements aremoveable relative to one another.
 2. The knee implant as claimed inclaim 1, wherein said hydromagnetic joint is disposed between said firstand second implant parts.
 3. The knee implant as claimed in claim 1,wherein at least one of said first and second implant parts comprises ananchoring post.
 4. The knee implant as claimed in claim 3, wherein saidhydromagnetic joint is disposed within said anchoring post.
 5. The kneeimplant as claimed in claim 4, wherein said first implant part includessaid anchoring post.
 6. The knee implant as claimed in claim 4, whereinsaid second implant part includes said anchoring post.
 7. The kneeimplant as claimed in claim 1, wherein said first and secondmagnetically charged surfaces have a common polarity so that said firstand second magnetically charged surfaces repel one another.
 8. The kneeimplant as claimed in claim 1, wherein said fluid body comprises aliquid or a gel.
 9. The knee implant as claimed in claim 8, wherein saidliquid or gel is medicated and said enclosure comprises one or moreopenings adapted to leech said medicated liquid or gel into an areasurrounding said intervertebral implant.
 10. The knee implant as claimedin claim 1, wherein said enclosure is a flexible enclosure adapted tochange shape as said first and second implant parts move relative to oneanother, and wherein said fluid body and said flexible enclosure areadapted to change shape in response to compression forces exerted uponsaid first and second implant parts.
 11. A knee implant comprising: afirst implant part including a first magnetic element having amagnetically charged surface, and a first buoyant element coupled withsaid first magnetic element; a second implant part opposing said firstimplant part, said second implant part including a second magneticelement having a second magnetically charged surface that opposes saidfirst magnetically charged surface of said first magnetic element, and asecond buoyant element coupled with said second magnetic element; afluid disposed between said first and second implant parts, wherein saidfirst and second implant parts are moveable relative to one another andare in fluid communication with said fluid.
 12. The knee implant asclaimed in claim 11, wherein said fluid is contained within an enclosurethat is disposed between said first and second implant parts.
 13. Theknee implant as claimed in claim 12, wherein said enclosure for saidfluid is flexible, and wherein said fluid is medicated.
 14. The kneeimplant as claimed in claim 11, wherein said first and second parts aremoveable relative to one another.
 15. The knee implant as claimed inclaim 11, wherein said first and second parts are adapted to move towardone another for compressing said fluid therebetween.
 16. The kneeimplant as claimed in claim 11, wherein said first and secondmagnetically charged surfaces have the same polarity and are adapted torepel one another.
 17. The knee implant as claimed in claim 11, furthercomprising: a first anchoring post coupled with said first implant partfor anchoring said first implant part to a femur; and a second anchoringpost coupled with said second implant part for anchoring said secondimplant part to a tibia.
 18. The knee implant as claimed in claim 17,wherein said first and second magnetic elements are disposed within saidfirst anchoring post.
 19. The knee implant as claimed in claim 17,wherein said first and second magnetic elements are disposed within saidsecond anchoring post.
 20. A knee implant comprising: a first partincluding a first magnetic element having a magnetically charged surfaceand a first buoyant element coupled with said first magnetic element; asecond part including a second magnetic element having a secondmagnetically charged surface that opposes said first magneticallycharged surface of said first magnetic element and a second buoyantelement coupled with said second magnetic element; and a fluid disposedbetween said first and second parts, wherein said first and second partsare in fluid communication with said fluid and are adapted to moverelative to one another.